From e0f35a5f0d903c7049b62658e4049bb8a48caac4 Mon Sep 17 00:00:00 2001
From: Adam Barth <abarth@chromium.org>
Date: Mon, 30 Nov 2015 14:58:56 -0800
Subject: [PATCH] Add a default onEnter/onExit for EnterExitTransition

We now default to the identity transition.
---
 packages/flutter/lib/src/widgets/enter_exit_transition.dart | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/packages/flutter/lib/src/widgets/enter_exit_transition.dart b/packages/flutter/lib/src/widgets/enter_exit_transition.dart
index 7b6dbee953c..771b9984317 100644
--- a/packages/flutter/lib/src/widgets/enter_exit_transition.dart
+++ b/packages/flutter/lib/src/widgets/enter_exit_transition.dart
@@ -93,14 +93,16 @@ class _Entry {
 
 typedef Widget TransitionBuilderCallback(PerformanceView performance, Widget child);
 
+Widget _identityTransition(PerformanceView performance, Widget child) => child;
+
 class EnterExitTransition extends StatefulComponent {
   EnterExitTransition({
     Key key,
     this.child,
     this.duration,
     this.curve: Curves.linear,
-    this.onEnter,
-    this.onExit
+    this.onEnter: _identityTransition,
+    this.onExit: _identityTransition
   }) : super(key: key) {
     assert(child != null);
     assert(duration != null);